Information for small house enthusiasts.

Kitchen Plumbing

Kitchen Plumbing Ideas to Keep in Mind

Most homeowners can do their own kitchen plumbing design, installation, and repairs. When you are working with kitchen plumbing, you need to remember that normal plumbing concepts prevail, and that simpler is always better.

If you are designing a kitchen from scratch, you have a lot of flexibility in how you want to design your layout. If possible, place your dishwasher close to the sink and the sink near existing plumbing lines. Often you can design your wet wall to back up to a bathroom, which will save you time and materials when you install the plumbing, but this is not necessary. You can run plumbing anywhere that you like, even into a kitchen island for a secondary sink, or dishwasher. The only plumbing difficulty is providing venting for an island sink, but this problem can be solved by using a one way vent under the counter top.

When you are adding plumbing to the opposite side of a wall, (a shower/tub for example) remember to reverse the hot and cold supply lines. This detail is easy to overlook until it is too late, and then it is harder to correct. Building codes require that hot water supplies be on the left and cold water supplies be on the right, but if you forget this detail in your house, you can easily handle the problem by crossing the flexible supply lines under the sink to the kitchen faucet. This may be a problem when you want to sell the house, however.

When you add a dishwasher to your kitchen plumbing configuration, there are a couple of items to keep in mind. The water supply line needs to be connected to the hot water supply. It is a good idea to have a separate shut-off valve for the water supply to the dishwasher. You can buy a dual outlet shut-off valve so that you can shut off the water to either the sink or the dishwasher without disrupting the supply to the other line.

The dishwasher discharge hose is designed to be attached to the garbage disposal under the sink. Make sure that the plug inside the garbage disposal is removed, or you will have water leaking out your dishwasher, and you won’t know why. If you don’t have a garbage disposal, this may be a good time to add one. You can also buy a drain tailpiece that has a dishwasher connector and you can then attach your dishwasher discharge hose to the connector.

One last point to keep in mind is that all kitchen drains are inch and a half in diameter, while bathroom drains are inch and a quarter. (This makes no sense to me either, but that’s the way it is.)